The present invention relates to a rolling flat cutter, and more particularly to a flat cutter for rolling a workpiece which consists of a pipe or a solid shaft to press a spline, serration or the like to its periphery, and a method of rolling the workpiece by the flat cutter.
As a conventional flat cutter, there is a rolling flat cutter as shown in FIG. 1, for example.
The conventional flat cutter as shown comprises a rectangular solid body 2 which has a plurality of corrugated working blades 3 formed to extend in width on an upper surface of the body, the working blades 3 consisting of rough blades 4, medium blades 5 and finishing blades 6, which gradually increase in height from an initial portion to a terminal portion of the cutter body in a longitudinal direction.
At the time of working, as shown in FIG. 2, a pair of flat cutters 1 are disposed with the working blades 3 thereof facing each other, so that a tubular or cylindrical workpiece 7 is charged between them with the axis of the workpiece extending in a parallel direction to the blades 3. Then, both of the flat cutters 1 are moved rectilinearly with respect to each other in opposite directions so that the peripheral portion of the workpiece 7 can be rolled.
In such a conventional flat cutter 1, since the working blades 3 which are formed through a width w of the body 2 roll the portion of the workpiece 7, a load from the working blades 3 is high, and particularly if the workpiece 7 is a pipe member, the workpiece is deformed in an axial direction, and thus the precision of working is reduced. According to the prior art, for solving such a problem, a workpiece which consists of a solid shaft is used and rolled on a periphery thereof, and then the workpiece is cored by a drill.
However, there are problems in that it takes additional time to core the workpiece and the working thereof is complicated. In addition, in the conventional flat cutter 1, since the working blades 3 are formed horizontally throughout a width w of the body 2, the working blades 3 are worn out evenly in the direction of width of the body 2. Therefore, it is difficult to extend the life of a cutter by reabrading the worn portion of the working blades.